Phenylalanine ammonia-lyase (PAL) is a plant enzyme which catalyses the non-oxidative elimination of ammonia from L-Phe to give trans-cinnamate. Trans-cinnamate is the precursor of numerous phenylpropanoid compounds and plays an important role in plant development and plant stress response. PAL may become a useful palliative for phenylketonuria as it has been shown to be able to convert excess Phe (toxic) in the blood into harmless compounds. It follows the same catalytic mechanism as tyrosine ammonia-lyase (TAL) for the deamination of L-tyrosine to (E)-4-coumarate.
Defined by 3 residues: TYR:A-110ASP:A-349 [auth A-351]GLY:A-398 [auth A-400]